Hi, 2 Years Ago I Had A Left Upper Lobectomy

hi, 2 years ago I had a left upper lobectomy for lung cancer. I have never been a smoker. Prior to surgery I had pneumonia 6 times. I have had it twice since the surgery. My specialist says I have much scarring. I am trying to get fit, but I find my lung capacity hasn't improved even when working out with a personal trainer for 6 months. Will my fitness ever improve or is this the best I'm ever going to get and just be thankful I'm here. Jane